Hi, how are the red a blue belts calculated? Because 24.686 items per sec translates correctly to 1.851 yellow belts (13.3 items/s), but 1.234 red belts, which are supposed to be double (26.67 items/s)

Actually, looking by the code, I think you got multipliers wrong ;)

divisor for belts should be 40/3 and multipliers 1,.5,1/3 instead of 3
for yellow: x1/(40/3) which is equivalent to x3/40 (so it's ok)
for red: x.5/(40/3) which is equivalent to x3/80
for blue: x(1/3)/(40/3) which is equivalent to x1/40 (so it's ok)

Update 1.0.6 should fix this, thanks!